The present inventive concepts relates to a display device, and more particularly, to an electrochromic display device.
An electrochromic display device is a device of which a transmissive characteristic is changed in response to a change in color of an electrochromic material due to electric reduction-oxidation according to application of a voltage. An electrochromic device is being applied to various fields such as a smart window, smart mirror, display device, and camouflage device, since it is advantageous in that optical transmittance may be changed due to application of an electric field.
In particular, the electrochromic display device does not require a polarization plate, etc., and does not depend on a viewing angle. Furthermore, the electrochromic display device is non-emissive and has advantages of excellent ease of enlargement according simple structure, and capability of various colored emissions according to selection of a material.
However, due to a slow speed of response, it is difficult to implement an existing electrochromic display device with an active matrix. In addition, considering an electro-optical characteristic of an electrochromic element, an internal pressure of the electrochromic element is low compared to those of other display elements.
For example, a liquid crystal (LC) element and an organic light emitting diode (OLED) element are enabled to receive a voltage of 10 V and able to be tolerant to a voltage higher than that. However, the electrochromic element has a limitation in that the electro-optical characteristic is destroyed at a voltage of about 3V.